Biology subjects

Schwabenlander, M.

Publications and source records attributed to Schwabenlander, M..

3 recordsLinked to original sources

bioRxiv2025

Prion Seeding Activity in DNA Extractions: Implications for Laboratory Biosafety

Infectious prions (PrPSc) are largely resistant to proteolytic digestion, including proteinase K digestion. While nucleic acid extracts are generally considered non-infectious, we investigated whether standard DNA purification methods can co-purify PrPSc, posing an unrecognized biosafety risk. Two laboratories, the University of Minnesota Center for Prion Research and Outreach (MNPRO) and the Canadian Food Inspection Agency (CFIA), independently tested filter-based and magnetic bead-based DNA extraction kits using tissues from chronic wasting disease (CWD)-positive and -negative white-tailed deer (WTD; Odocoileus virginianus), as well as prion-infected and control Syrian hamster (Mesocricetus auratus) brains. CFIA used two filter-based kits (one automated and one manual), while MNPRO tested two manual kits (one filter-based and one magnetic bead-based). PrPSc seeding activity was measured in extracted DNA and source tissues using real-time quaking-induced conversion (RT-QuIC). MNPRO found substantial to almost perfect agreement (kappa ({kappa}) = 0.789 - 0.816) between RT-QuIC seeding activity of DNA eluates from both extraction methods and that of the source WTD tissue homogenate. CFIA optimized RT-QuIC to a 30-hour runtime, achieving 74% sensitivity and 94% specificity in 88 archived WTD DNA samples. Both laboratories concluded that commercial DNA extraction kits do not eliminate PrPSc, enabling its carry-over into DNA eluates. Until infectivity is resolved by animal bioassay, DNA from PrPSc-positive tissues should be managed under biosafety protocols appropriate for the originating prion disease, with appropriate decontamination and containment procedures.

molecular biology↗

bioRxiv2024

Detection and decontamination of chronic wasting disease prions during venison processing

Prion diseases, including chronic wasting disease (CWD), are caused by prions, which are misfolded aggregates of normal cellular prion protein. Prions possess many characteristics that distinguish them from conventional pathogens, in particular, an extraordinary recalcitrance to inactivation and a propensity to avidly bind to surfaces. In mid to late stages of CWD, prions begin accumulating in cervid muscle tissues. These features collectively create scenarios where occupational hazards arise for workers processing venison and pose risks to consumers through direct prion exposure via ingestion and cross-contamination of food products. In this work, we show that steel and plastic surfaces used in venison processing can be directly contaminated with CWD prions and that cross-contamination of CWD-negative venison can occur from equipment that had previously been used with CWD-positive venison. We also show that several decontaminant solutions (commercial bleach and potassium peroxymonosulfate) are efficacious for prion inactivation on these same surfaces.

microbiology↗

bioRxiv2021

A Field-Deployable Diagnostic Assay for the Visual Detection of Misfolded Prions

Chronic Wasting Disease (CWD), a prion disease of cervids, has been identified across North America, Northern Europe and Korea. Diagnostic tools for the rapid and reliable detection of prion diseases are limited. Here, we combine gold nanoparticles (AuNPs) and quaking induced conversion (QuIC) technologies for the visual detection of amplified misfolded prion proteins from tissues of wild white-tailed deer infected with Chronic Wasting Disease (CWD). Our newly developed diagnostic test, MN-QuIC, enables both naked-eye and light-absorbance measurements for the detection of misfolded prions. The MN-QuIC assay leverages basic laboratory equipment that is cost-effective and portable, thus facilitating real-time prion diagnostics across a variety of settings. To test the portability of our assay, we deployed to a rural field station in southeastern Minnesota and tested for CWD on site. We successfully demonstrated that MN-QuIC is functional in a non-traditional laboratory setting by performing a blinded analysis in the field and correctly identifying all CWD positive and CWD not detected (independently confirmed with ELISA and/or IHC tests) animals at the field site, thus documenting the portability of the assay. Additionally, we show that electrostatic forces and concentration effects help govern the AuNP/prion interactions and contribute to the differentiation of CWD-prion positive and negative samples. We examined 17 CWD-positive and 24 CWD-not-detected white-tailed deer tissues that were independently tested using ELISA, IHC, and RT-QuIC technologies, and results secured with MN-QuIC were 100% consistent with these tests. We conclude that hybrid AuNP and QuIC assays, such as MN-QuIC, have great potential for sensitive, field-deployable diagnostics for a variety of protein misfolding diseases.

molecular biology↗